The wet weather we have seen in some areas has caused perfect conditions for the formation of brown rot on stone fruits such as peaches and plums. Affected fruit develop a gray to brown, fuzzy growth on the fruit, itself, which may rot in as little as a day or two. It is best to start treating fruit about a month before harvest but spraying is still helpful even if we are within that one month period. Fruit that shows symptoms cannot be saved but should be destroyed to prevent further spread.
 
Use Captan or myclobutanil (Immunox) for control. Many fruit tree sprays contain Captan but check the label to be certain. Apply Captan or Immunox every 7 to 14 days.  Both products can be applied up to the day of harvest.  Note that though Immunox is labeled for fruit but Immunox Plus is not. (Ward Upham)

Modern annual flowers have been bred to flower early and over a long period of time. They are not as easily thrown off flowering by high nitrogen levels as vegetables are. As a matter of fact, providing nitrogen through the growing season (sidedressing) can help maintain an effective flower display for warm-season flowers.
 
Apply a high nitrogen sidedressing four to six weeks after flowers have been set out. Additional fertilizations every three to four weeks can be helpful during a rainy summer, or if flower beds are irrigated. Common sources of nitrogen-only fertilizers include nitrate of soda, urea, and ammonium sulfate. Blood meal is an organic fertilizer that contains primarily, but not exclusively, nitrogen. Use only one of the listed fertilizers and apply at the rate given below.
 
Nitrate of soda (16-0-0): Apply 1/3 pound (.75 cup) fertilizer per 100 square feet.
Blood Meal (12-1.5-.6): Apply 7 ounces (7/8 cup) fertilizer per 100 square feet.
​Urea (46-0-0): Apply 2 ounces (1/4 cup) fertilizer per 100 square feet.
Ammonium Sulfate (21-0-0): Apply 4 ounces (½ cup) fertilizer per 100 square feet.
 
If you cannot find the above materials, you can use a lawn fertilizer that is about 30 percent nitrogen (nitrogen is the first number in the set of three) and apply it at the rate of 3 ounces (3/8 cup) per 100 square feet. Do not use a fertilizer that contains a weed killer or weed preventer.  (Ward Upham)

It is important to leave spring-flowering bulb foliage in place until it “ripens” or becomes brown.  The energy produced by the leaves after flowering is transferred to the bulb so that it can flower the following year.
 
The ripening  process should be near completion about now for tulips, daffodils and various other spring- flowering bulbs.  Use clippers, scissors or even a mower to remove dead foliage.  Also, try to map out where the bulbs are planted as there will be no foliage to make the location next fall when it is time to fertilize.  (Ward Upham)

Rose rosette is a serious problem in Kansas on wild roses (Rosa multiflora) in pastures and hedges. It is also found in domestic rose plantings.
 
Infection is thought to start with rapid elongation of a new shoot. The rapid shoot growth may continue for several weeks to a length of two to three feet. Following shoot elongation, a witches' broom or clustering of small branches occurs. The stems develop excessive thorniness and produce small, deformed leaves with a reddish-purple pigmentation. Stems and petioles of Rosa multiflora plants may have reddish blotches or streaks.
 
Rose plants infected with the rose rosette virus die rapidly, usually within one to two years. Rose rosette is caused by a Emaravirus species.  Transmission of the disease has been shown experimentally through grafting and is also thought to be spread by mites. Though KnockOut roses are resistant to many diseases, they are susceptible to this one.
 
There is no effective control measure for infected plants. In garden settings, infected plants should be removed and destroyed, including roots. Any roots that remain after plant removal may produce infected shoots which can harbor the disease. If possible, eliminate all multiflora rose plants from the vicinity as they are extremely susceptible and will act as a carrier. Multiflora rose is the wild rose often seen growing in ditches and pastures.
 
Since the disease can be transmitted by pruning shears, disinfect the shears when moving from one plant to another by using rubbing alcohol or a disinfectant such as Lysol. (Ward Upham)

The European fruit lecanium scale (Parthenolecanium cornii) is quite noticeable on bald cypress (Taxodium distichum) twigs and branches. The damage associated with this scale, which depends on the extensiveness of the infestation, includes plant stunting and wilting. The European fruit lecanium scale is a soft scale, so honeydew (a sticky, clear liquid) will be produced during feeding. The honeydew serves as a substrate for black sooty mold and attracts ants. In addition, honeydew can drip onto vehicles parked underneath infested trees leaving unsightly residue.
 
The scales are dark brown, 1/8 to 1/4 inches in diamete. Some scales may have white markings on the body. European fruit lecanium scale overwinters as an immature on twigs and branches with maturing occurring in spring. In May and June, females lay many eggs underneath their bodies. In June eggs hatch into small tan-colored crawlers. The duration of an egg hatch can last several days depending on the temperature. Crawlers migrate to leaf undersides and subsequently feed on plant fluids until late summer. At that point, the crawlers migrate back onto twigs and branches to complete their development the following spring. There is one generation per year in Kansas.
 
Management of European fruit lecanium scale primarily involves timely applications of insecticides.  Applications should be made when crawlers are present because the crawlers are most vulnerable life stage to insecticide sprays. Mature scales possess a shell-like covering that protects them from exposure to insecticides. Repeat applications will be required as the eggs do not all hatch simultaneously but may hatch over a three to four-week period. The most appropriate time to apply insecticides is in late June to early July when the crawlers are feeding on leaves; thus enhancing their exposure to any spray residues. There are a number of insecticides, with contact activity that are effective in suppressing populations of the European fruit lecanium scale. However, many have broad-spectrum activity and will kill many natural enemies including: parasitoids and predators. In fact, most outbreaks of scale insects are caused by the indiscriminate use of pesticides (insecticides and miticides). Therefore, always read the label and exercise caution when applying any pesticide. In the winter, dormant oils can be applied to kill overwintering scales by means of suffocation.
 
I need to acknowledge Jeff Otto of Wichita, KS for bringing to my attention that European fruit lecanium scale was active. I have also observed infestations in Manhattan, KS.  (Raymond Cloyd)

As with many areas in Kansas, Sedgwick County has seen a high level of oak vein pocket gall this year. Matthew McKernan, our Sedgwick County Horticulture Agent and Dr. Raymond Cloyd, our Horticulture Extension Entomologist, have put together a two page fact sheet discussing the problem. Excellent photos and informative text make this a timely and valuable resource for those who need more information on this subject. You can find the publication at: http://www.hfrr.k-state.edu/doc/hort-tips/Oak-Vein-Pocket-Gall.pdf
(Ward Upham)

Ticks are very active throughout the state, and have been for the past month. The most commonly reported
species has been the American dog tick, Dermacentor variabilis.

The cool, humid weather over the past month has provided great conditions for tick development.  These annoying, and potentially dangerous parasites have even been encountered in corn fields, which is unusual as they typically develop in more undisturbed areas of grasses, weeds, and other overgrown vegetation. But, they are very good at finding hosts and getting the blood meal they require for development and reproduction. For more information on ticks in Kansas, please visit: https://www.vet.k-state.edu/vhc/docs/ticks-in-kansas.pdf.  (Jeff Whitworth and Holly Schwarting)

Many bagworms have hatched and have come out of the mother's bag but we are still a bit early to treat as we may miss those that are late to emerge.  The latter half of June is a good target to treat for these insects. However, make sure you have living bagworms as sometimes natural predators and parasites provide good levels of control. Look for a miniature version of the mature bagworm. They are still tiny and are about the size of the lead point on a pencil.
 
Insecticides commonly used for controlling bagworms include spinosad (Conserve; Fertilome Borer, Bagworm, Leafminer & Tent Caterpillar Spray; Captain Jack’s Dead Bug Brew, Bonide Caterpillar Killer), Bacillus thuringiensis (Dipel, Thuricide), acephate (Acephate, Orthene, Bonide Systemic Insect Control), cyfluthrin (Tempo, Bayer Vegetable & Garden Insect Spray) and permethrin (numerous trade names). Products containing Bacillus thuringiensis (BT) are only effective when used against bagworm larvae while they are still small. Note that spinosad and BT are both organic but spinosad is a more effective product, especially on larger larvae.
 
Thorough coverage is vital for good control. Most failures are due to the spray not penetrating deep enough in the tree rather than the insecticide not working. (Ward Upham)

Some areas of Kansas have had saturated or near-saturated soils for several weeks now. Gardeners are likely to assume that watering won’t be needed for quite some time now as soil moisture levels are very high. Actually, watering may be needed much sooner than you expect. Excessive rain can drive oxygen out of the soil and literally drown roots.
Therefore, as we enter hotter, drier weather, the plants with damaged root systems may be very susceptible to a lack of water. Don’t forget to check your plants for signs of wilting or leaf scorching and water as needed.
 
If irrigation is called for, water deeply and infrequently. Usually once per week is sufficient depending on the weather. Soil should be moist but not waterlogged. (Ward Upham)
 
Contributors: Raymond Cloyd, Extension Entomologist; Holly Schwarting, Entomology; Ward Upham, Extension Associate; Jeff Whitworth, Entomology

Many gardeners look forward to harvesting new potatoes this time of year. New potatoes are immature and should be about the size of walnuts. Pull soil away from the base of the plants to see if the tubers are the desired size. If they are, dig entire plants and allow the skins of the exposed tubers to dry for several hours before gathering. These young potatoes are very tender and prone to the skin “slipping” unless they are given a few hours to dry. Even then these immature potatoes will not store well. Red-skinned varieties are often preferred as they are the earliest to produce. (Ward Upham)

Though tomatoes need to be fertilized to yield well, too much nitrogen can result in large plants with little to no fruit. Tomatoes should be fertilized before planting and sidedressed with a nitrogen fertilizer three times during the season.

The first sidedressing should go down one to two weeks before the first tomato ripens. The second should be applied two weeks after the first tomato ripens and the third one month after the second. Common sources of nitrogen-only fertilizers include nitrate of soda, urea, and ammonium sulfate. Blood meal is an organic fertilizer that contains primarily, but not exclusively, nitrogen. Use only one of the listed fertilizers and apply at the rate given below.

Nitrate of soda (16-0-0): Apply 2/3 pound (1.5 cups) fertilizer per 30 feet of row.

Blood Meal (12-1.5-.6): Apply 14 ounces (1.75 cups) fertilizer per 30 feet of row.

Urea (46-0-0): Apply 4 ounces (½ cup) fertilizer per 30 feet of row.

Ammonium Sulfate (21-0-0): Apply 0.5 pounds (1 cup) fertilizer per 30 feet of row.

If you cannot find the above materials, you can use a lawn fertilizer that is about 30 percent nitrogen (nitrogen is the first number in the set of three) and apply it at the rate of 1/3 pound (3/4 cup) per 30 feet of row. Do not use a fertilizer that contains a weed killer or weed preventer. (Ward Upham)

We should have good fruit crops this year as long as we can avoid severe weather. Keep in mind some tips to help insure healthy trees, vines and fruit.

* Remove fruit from heavily loaded apples and peaches (if the flower buds weren’t killed by frost) to improve fruit size and prevent limbs from breaking. Apples should be spaced every 4 inches and peaches every 6 to 8. Note that is an average spacing. Two fruit can be closer together if the average is correct.

* Remove sucker growth from the base of fruit trees and grape vines.

* Remove water sprout growth from fruit trees. Water sprouts grow straight up.

* "Comb" new growth on grape vines so these new shoots hang down for greater exposure to sunlight.

* Continue disease and insect control to prevent fruit damage. (Ward Upham)

One of the most important clues in determining the health of your trees is the amount of new growth that tree produces. A healthy tree should have a minimum of 4 to 6 inches of new growth each year. Check branches with the tips in the open and not shaded by the tree itself. Anything less than 4 inches on the majority of branches suggests the tree is under a great deal of stress.

So how do you tell where the new growth stops? Look for a color change in the stem. New growth is often greener than that from the previous year. There is also often an area of what looks like compressed growth where growth transitions from one year to the next.

Lastly, look at leaf attachment. Leaves are only produced on current seasons’ growth. Therefore, new growth stops where leaves are no longer attached directly to the twig but to side branches. However, pay attention as leaves may be appear to be attached directly to last year’s growth but are actually borne on short spurs. If you look closely, you can tell the difference.

All this clue tells you is whether a tree is under stress or not. It does not tell you what is causing poor growth. This year, the most common cause by far is environmental stress caused by the sharp drop in temperature in November. However, the dry winter and excess moisture this spring has also contributed to stress.

Stress is cumulative. In other words, trees may not have completely recovered from stressful conditions (such as drought) that occurred within the last several years. The accumulating stress may have damaged root systems with further damage occurring due to saturated soils this spring. These trees may struggle as we enter summer. Though the roots were able to keep up with moisture demands during the cooler spring weather, they may not be able to as temperatures rise. Such trees may suddenly collapse and die or slough off branches they can no longer support. If
possible, water to a depth of 12 inches every couple of weeks we do not receive rain in order to avoid further stress. (Ward Upham)

Now is a good time to start new trees and shrubs from existing ones. Many ornamental trees and shrubs can be reproduced by taking cuttings from new growth that occurred this spring. Though these softwood cuttings root relatively easily, they are susceptible to wilting and need close attention to watering and relative humidity.

It is best if cuttings are taken after a rain or several hours after the plant has been well watered to ensure the cuttings remain turgid. Stems should be mature enough that they snap rather than bend when placed under pressure. Cuttings should be about 6 inches long with cuts made at an angle just below a node, the area where a leaf joins the stem. The angle provides a larger cut surface and more area for the cutting to callus and root.

Strip off the lower leaves and place the cutting in a moist rooting media after it has been dipped in rooting powder. Several rooting mediums are suitable including sand with peat moss, sand with vermiculite, perlite with peat moss, and perlite with vermiculite. A suitable medium should provide good moisture-holding capacity and be open enough to provide good aeration to the roots. Though some plants can be rooted directly in water, roots formed in water do not adapt well to soil.

Rooting containers vary. Some gardeners prefer flats because the number of cuttings each will hold. Others prefer small, individual pots for each cutting so cuttings can be removed from the propagation environment as they root. Regardless of the container used, relative humidity should be kept at a high level.

This can be done by enclosing the container or containers in a plastic bag. Use wooden dowels, plastic straws or a similar object to keep the plastic off the top of the cuttings. Place the rooting container in bright, indirect light and check often for watering needs. When roots are about 1 inch long, cuttings can be removed from the propagation chamber and potted. (Ward Upham)

Many people mistake little barley (Hordeum pusillum) for a little foxtail because the foxtail and little barley seedheads are similar. However, little barley is a winter annual that thrives in the cooler spring temperatures but dies out in the summer. Foxtail, on the other hand, is a summer annual that does well in hot weather. Also, foxtail will not produce seedheads until mid- to late-summer.

At this point there is no control for little barley other than a glyphosate product such as Roundup. However, Roundup will kill whatever it hits and cannot be used in a lawn situation. The only preemergence herbicide that I know is labeled for lawn situations is Surflan. Monterey Lawn and Garden also sell it under the name of Weed Impede. Surflan can only be used on warm-season grasses (bermudagrass, buffalograss, zoysiagrass) and tall fescue grown in warm-season areas. Because little barley is a winter annual, apply the preemergence herbicide in September. (Ward Upham)

Waterlogged soils push out oxygen that roots need to survive. Every living cell in a plant must have oxygen or it dies. Some plants have mechanisms to provide oxygen to the roots even under saturated conditions but most of our
vegetables and flowers do not. The longer these plants are subjected to saturated soils, the more likely damage will occur.

Usually, as long as water drains away within 24 hours, the impact on plant health is minimal. However, shallow, stagnant water under hot, sunny conditions can literally cook plants, reducing survival time to as little as a few hours.

Vegetables: What about safety regarding eating produce from a garden that has been flooded? Standing water should not cause a safety problem as long as the aboveground portions of the plant remain healthy. Do not use produce from plants that have yellowed. Also, using produce flooded with water contaminated with sewage (lagoon) or animal manure can also be dangerous.

The safest approach is to discard all garden crops that have been in contact with such water. Certainly, leafy vegetables should always be discarded. However, you may eat fruit from such crops as tomatoes, peppers, eggplants, sweet corn, squash, cucumbers, and similar vegetables that develops after the waters have subsided as long as the fruit is not cracked or soft. Always wash vegetables thoroughly before eating.

Lawns: Under the cool conditions of early spring, turfgrasses can often survive several days of flooding. However, during hot, sunny conditions with shallow, stagnant water, lawns may be damaged quickly, sometimes in a few hours. This situation often occurs when shallow depressions in a lawn allow water to pool. Note such areas and fill in with additional soil once the waters have subsided.

Trees: Trees differ markedly in their ability to withstand flooding. Some trees have mechanisms in place to provide oxygen to the roots of plants with water saturated soils and others do not. However, most trees will maintain health if flood waters recede in 7 days or less. It also helps if water is flowing rather than stagnant as flowing water contains more oxygen. If the roots of sensitive trees are flooded for long periods of time, damage will occur including leaf f drop, iron chlorosis, leaf curl, branch dieback, and in some cases, tree death. Another danger of flooding is the deposition of sediment. An additional layer of silt 3 inches or more can also restrict oxygen to the roots. If possible, remove deep layers of sediment as soon as conditions permit. This is especially important for small or recently transplanted trees.

Try to avoid any additional stress to the trees this growing season. Ironically, one of the most important practices is to water trees if the weather turns dry. Flooding damages roots and therefore the root system is less efficient in making use of available soil water. Timely waterings are vital to a tree’s recovery. Also be diligent in removing any dead or dying branches which may serve as a point of entry for disease organisms or insect pests. The following information on tree survival came from the US forest Service.

Trees Tolerant of Flooding: Can survive one growing season under flooded conditions. Red maple, silver maple, pecan, hackberry, persimmon, white ash, green ash, sweetgum, sycamore, eastern cottonwood, pin oak and baldcypress.

Trees Moderately Tolerant of Flooding: Can survive 30 consecutive days under flooded conditions. River birch, downy hawthorn, honeylocust, swamp white oak, southern red oak, bur oak, willow oak and American elm.

Trees Sensitive to Flooding: Unable to survive more than a few days of flooding during the growing season. Redbud, flowering dogwood, black walnut, red mulberry, most pines, white oak, blackjack oak, red oak and black oak.

After the Flood: Soils often become compacted and crusted after a heavy rainfall. This also can restrict oxygen to the roots. Lightly scraping the soil to break this crust will help maintain a healthy root system and therefore, a healthy plant. Be careful not to cultivate too deeply as shallow roots may be damaged. If you think the excessively wet weather will continue, bedding up the rows before planting even just a couple of inches, will improve drainage and allow for better aeration. (Ward Upham)

Contributors: Ward Upham, Extension Associate